Oxidized cellulose (6-carboxycellulose, OC) containing 3-25% carboxylic acid groups is a biocompatible, bioresorbable polymer. (See e.g. U.S. Pat. No. 3,364,200). Currently, OC containing 16-24% carboxylic acid groups is used in humans as a hemostatic agent and as a postsurgical adhesion barrier. Despite its widespread use in medicine and related areas, OC has found little use in pharmaceutical applications. This is because it is practically insoluble in water and common organic solvents and, hence, offers little or no formulation flexibility.
Accordingly, it is a primary objective of the present invention to provide novel, biodegradable polymers for potential applications as biodegradable polymers in drug delivery, tissue engineering, and related areas.
It is a further objective of the present invention to provide oxidized cellulose esters, and novel dosage forms of the same.
It is a further objective of the present invention to provide oxidized cellulose carboxylate alkyl esters as a new class of biodegradable polymers.
It is still a further objective of the present invention to provide a method and means of preparing a microsphere dosage form for camptothecin, 5-fluorouracil, and other water soluble or insoluble drugs that provides for effective controlled release of the drug.
The method and means of accomplishing each of the above objectives as well as others will become apparent from the detailed description of the invention which follows hereafter.